Human embryo at the six week stage
Human embryo at six weeks with budding arms and legs, and yolk sac. Image: Shutterstock.

By the sixth week, you are well into your second month of pregnancy. By this time, your baby is about the size of a sweet pea (sugar snap pea) or a grain of rice, measuring between 0.5 and 2 centimetres from crown to rump. Embryos are not measured from head to toe because they are usually curled up, which makes it difficult to tell the exact height.

pregnancy week by week 6 baby weight and size compared to fruit

Your baby at 6 weeks

By now your baby is settling comfortably in its new home and continuing to grow. The placenta is still in development and the embryo is still feeding on the embryo sac. The placenta will have fully formed by the eighth week of pregnancy, where it will be ready to take over from hCG and the embryo sac.

Throughout week six, your baby will go through a lot of growth and development. The neural tube along the embryo’s back closes during this week. The baby’s brain and spinal cord will develop from this tube. The nervous system also starts to form.

Your baby’s head starts to take shape and the structures that are necessary for the formation of the eyes and ears also begin to develop. The ears appear as bumps on the side of the embryo’s head. Your baby’s cheeks, chin and jaw have also begun to form. The limbs also start to grow, although they only appear as tiny buds on the embryo’s body.

Many other internal organs have also begun to form. The brain, kidney, liver and lungs have started taking shape. The embryo also has a thin layer of skin and the teeth have already started forming.

Also, some good news: your baby’s heartbeat can now be felt! A vaginal ultrasound will be able to detect a heartbeat at this stage of pregnancy. The baby’s heart beats at 105 beats per minute. However, if your ultrasound doesn’t reveal a foetal pole or a heartbeat, it is no cause for alarm and your doctor might call you for another ultrasound later in your pregnancy. A foetal pole is the first visible sign of a developing embryo.

If you are expecting twins, an ultrasound during this week may also be able to detect both their heartbeats. You might see two embryo sacs or two foetal poles.

Your body at 6 weeks

It is still quite early in your pregnancy. Some women are still barely experiencing any symptoms at this time. If you are showing no signs of pregnancy, that’s perfectly normal. However, generally speaking, most women will have some or all of the following common symptoms by the sixth week:

  • Tummy trouble. Stomach discomfort often occurs due to a build-up of progesterone. It is common to experience bloating, gas, indigestion and constipation. Constipation can also be as a result of the increased iron intake from the prenatal vitamin supplements. You might also experience indigestion and heartburn, which happen because the muscle at the top of the stomach relaxes. This muscle’s job is to prevent digestive juices from backing up, and it starts failing at this job. To prevent this, you should drink plenty of fluids. Increasing your fibre consumption will also help. You can do this by eating lots of vegetables, fruits, wholegrain cereals, and nuts. You should also exercise, not only because it is great for keeping your body and mind in shape, but also because it helps to prevent constipation. About 75% of women experience morning sickness during pregnancy. The cause of the nausea is unknown but is usually a result of an increase in the hCG hormone. There are several things you could do to feel better. You might want to stay away from spicy and greasy foods and eat a blander diet. Try not to lie down immediately after you eat. If you have been vomiting, you should drink plenty of fluids to stay hydrated. A telltale sign of dehydration is dark yellow urine.
  • Breast tenderness. This is a recurring symptom of pregnancy. Your breasts will likely feel sore on and off until childbirth. However, for some women, the feeling goes after the first trimester. Sore breasts are a result of the increased blood flow in your body. You may also notice your areolas – the skin around the nipple – getting darker and your nipples sticking out. This is just your body making the preparations for breastfeeding. Wearing a supportive bra would really help to reduce the discomfort.
  • Frequent urination. This is completely normal and might get worse as your pregnancy progresses. hCG directs more blood flow to the pelvic area, causing faster urine production. Also, as your baby continues to grow, they press down your bladder, reducing your pee storage capacity. It is important to remember to always go to the bathroom when you feel pressed and not to hold it in. This will help reduce the risk of getting a bladder infection. If, however, you experience any pain while urinating, or you are unable to go even when you feel like you have to, tell your healthcare professional right away. These are symptoms of a urinary tract infection, which, starting at week six, you have a higher chance of contracting. Your doctor can prescribe baby-safe medicine to treat it.
  • Cramping and spotting. It is common to experience light bleeding and abdominal pain during these early stages of pregnancy. However, if the pain feels too severe, and/or the bleeding is heavy, you should tell your healthcare professional immediately.

At six weeks, although you might feel and look bloated, it is still difficult for anyone else to tell that you are pregnant.

Taking care of yourself during this time

Stay away from hot tubs, saunas, and tanning beds. Temperatures above 38.5 degrees Celcius can increase the risk of miscarriage and foetal abnormalities. Now that the reality of pregnancy is slowly sinking in, you need to drink a lot of water. Dehydration can cause serious complications like low amniotic fluid and inadequate breast milk production.

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